Category: Earth

For several years, astronomers have known that rings of dust follow the planets Earth and Venus in their journeys around the Sun. Researchers have now found a similar ring of dust also accompanies Mercury in its orbit, much to the surprise of astronomers, who believed any system like this would be driven away by the Sun. Our own ring is produced by collisions between bodies in the asteroid belt between Mars and Jupiter, but computer simulations have shown the ring bonded with Venus is likely the result of a previously-unknown asteroid belt around the orbit of that planet.

Science fiction is filled with stories of astronauts blowing up asteroids just before they strike the Earth. But, doing so could be even worse than doing nothing, as fragments of these bodies could impact the Earth in multiple locations, like a shotgun blast. Now, new research from Johns Hopkins University shows even attempting to blow up an asteroid might prove futile. Computer models of impacts between two asteroids show that such events would likely result in short-term fragmenting of the bodies, but these pieces would come together again within hours, recreating a mass much like the original asteroid. Researchers are on the lookout for asteroids and comets heading toward the Earth that could endanger areas from small cities to the entire planet.

Most dinosaurs were wiped out 66 million years ago, but scientists are still trying to piece together exactly what caused their demise. An asteroid, at least as large as Mount Everest, struck the Earth at that time, likely leading to the extinction of all non-avian dinosaurs. However, new research suggests that volcanic activity at Deccan Traps in India may have doomed the animals before the asteroid struck off the coast of Mexico. A series of four massive pulses of eruptions there released enough lava to build a ring one mile thick and five miles across that would encircle the globe. These events also released vast quantities of poisonous gas into the atmosphere, and created extreme global warming, raising temperatures worldwide. This climate change may have weakened the line of dinosaurs so much, they were unable to withstand the additional climate change which happened once the asteroid hit the Earth.